Before getting to the review, I would like to open by noting that COVID protocols are all over the map for schools and ensembles.
I think the setup we are using at Arizona State is as good as anywhere, in terms of being a good learning environment and relatively safe. The basic initial protocol we have for brass playing in a practice room is that after a practice session the room has to be empty for an hour. There is an online sign up system and so far it is working well. Students are also responsible to clean the room after their session, and only certain rooms are allowed for brass/wind/voice practice.
My office has the same basic restriction, after a lesson where a student plays the office has to be vacant for an hour after the lesson. I am starting the semester rotating students that want live lessons (not all do) through the last lesson slot of the day. When it gets cooler outside I will open up another live lesson slot before lunch a couple days a week too, when I can vacate the office for an hour after a lesson (eating lunch outside, or taking a walk). There is also an air purifier, and we wear masks when not playing. In addition, my office is big enough that I am sitting a full 16 feet away from the student! We have space.
What is great about this from my perspective is I can get an accurate feel for the playing of a student live in a room. This is all that made the spring work, really; I was very familiar with all the students before we shut down for COVID. Rotating live lessons with the Zoom lessons will help me a lot as a teacher, as will students being able to practice in practice rooms.
[Also, note in the photo my spittoon! People are concerned about our condensation, and I have collection of condensation covered in my office.]
Ensembles here are starting online with recording projects, hopefully moving live later in the semester. Not to give away too many secrets, we are making use of the Bandlab platform to do collaborative recording projects at ASU. If you are looking for something like this to enhance a teaching or ensemble experience, this one is worth looking at.
As our ensembles are starting online, the topic of bell covers has not been an issue yet. However, I did get one, from Houghton Horns, purchased on my own without thinking I would review it, but it is a product of current interest. In terms of horn playing you hardly notice it for sound or feel of the instrument. What you do notice is that your hand in the bell gets warm; the hot air of your breath is held back to some extent by the bell cover. I do not know how much it really works, but if health protocols require it in your situation it has no negative impact on your playing.
[UPDATE: For more on the topic of bell covers see: https://smtd.colostate.edu/reducing-bioaerosol-emissions-and-exposures-in-the-performing-arts/]
A final note being you can make tons of progress as a horn player this fall! Do not give up without trying for sure; you can make much good use of your time if you choose to.